AT-426
[RE5F22A]
A/T CONTROL SYSTEM
Revision: November 2006
2006 Altima
SMOOTH LOCK-UP CONTROL
When shifting from the lock-up released state to the lock-up applied state, the current output to the pressure
control solenoid valve C is controlled with the TCM. In this way, when shifting to the lock-up applied state, the
torque converter clutch is temporarily set to the half-clutched state to reduce the shock.
Half-Clutched State
●
The current output from the TCM to the pressure control solenoid valve C is varied to steadily increase the
pressure control solenoid valve C pressure.
In this way, the lock-up apply pressure gradually rises and while the torque converter clutch piston is put
into half-clutched status, the torque converter clutch piston operating pressure is increased and the cou-
pling is completed smoothly.
Slip Lock-up Control
●
In the slip region, the pressure control solenoid valve C current is controlled with the TCM to put it into the
half-clutched state. This absorbs the engine torque fluctuation and lock-up operates from low speed.
This raises the fuel efficiency for 4th and 5th gears at both low speed and when the accelerator has a low
degree of opening.